Lock



FIG. 1 is a front perspective view of a lock showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken line showing of the circular keyway region and the remainder of the lock represents unclaimed subject matter and forms no part of the claimed design. 

CLAIM The ornamental design for a lock, as shown and described. 